Fire detector



FIG. 1 is a bottom perspective view of a fire detector showing my new design;

FIG. 2 is a front elevation view;

FIG. 3 is a rear elevation view;

FIG. 4 is a right side elevation view;

FIG. 5 is a left side elevation view; and,

FIG. 6 is a bottom view, the top view not being shown since it is of a functional nature. 

The ornamental design for a fire detector, as shown. 